Conventional processes often take place in a high-temperature chamber which contains a corrosive gas. For instance, a Cu/In/Ga/Se solar cell selenization process has to measure the gas pressure in the chamber to control the process and ensure stable product quality. In general, for a low-vacuum CIGS selenization process, the processing gas pressure ranges from medium vacuum to rough vacuum, i.e., 10e-2˜760 torr and an operating temperature of 300° C.˜680° C.
The operating temperature of a conventional vacuometer or pressure gauge (say US 20040089073) for measuring the chamber gas pressure is limited by the heat resistance characteristics of related elements and the materials which the inner part of the conventional vacuometer or pressure gauge is made of. Furthermore, the pressure gauge for a high-temperature corrosive gas has its sensing components exposed to the high-temperature corrosive gas and thus must be made of a corrosion-resistant and heat-resistant material. In addition, regardless of whether the gas pressure is measured by mechanical or electrical manner, an algorism must be considered for compensating or correcting the issues caused by the constitution of the gas to measure and the operating temperature, not to mention that it has to consider the influences by the thermal expansion of the gas and the thermal sensitivity of the pressure gauge. As a result, the conventional vacuometer or pressure gauge is flawed with imprecise measurement and high costs.
Accordingly, it is imperative to provide a high-temperature pressure measuring method with a view to overcoming the aforesaid drawbacks of the prior art.